期刊名称：International Journal of Computer Trends and Technology
电子版ISSN：2231-2803
出版年度：2013
卷号：4
期号：6-2
出版社：Seventh Sense Research Group
摘要：despite the advent of several other kinds of transmitting media such as satellite, optical fibre, coaxial cables etc., wireless channel continues to be used extensively owing to the fact that it is economical and flexible. When comparison is to be made between two or more systems over a real channel, they must all be tested simultaneously. Unlike cables, whose properties can be accurately defined and reproduced, Ionosphere channel properties can't be reproduced easily. The channel characteristics and transmission conditions vary uncontrollably. Hence tests can't be repeated at other times. Moreover it is not possible to test a system repeatedly for the same channel conditions. The use of a channel simulator for evaluating the performance of a data transmission system offers several advantages. It is accurate and a large range of channel conditions using various data. It is possible to compare the channel conditions using a channel simulator. And tests can be repeated any number of times with consistent channel transmitting conditions. By using Randomization process data is divided into small units randomly such that each unit is sent through different paths with automatic calculation of frequency.
